Add instructions for homework.

README.md

-# `git` training: repo for pratice and homework
+# Repo for pratice and homework
 
+## Homework on GitLab
+
+*This exercise has to be done on your lab computer on which `Matlab` **is** installed. Don't forget to properly configure `git` with your username and email, as we explained in the training slides.*
+
+<br>
+During the training, you committed to the
+<br>
+[https://git-r3lab.uni.lu/git-training/practice](https://git-r3lab.uni.lu/git-training/practice)
+repository.
+
+<br>
+Your task is to create a fork of this repository, commit some code and create a merge request on `GitLab`.
+
+
+## Homework: instructions
+
+- First, fork the [https://git-r3lab.uni.lu/git-training/practice](https://git-r3lab.uni.lu/git-training/practice) repository.
+
+- Create the new branch `homework_myName`.
+
+- Implement a new function (create a new file `sqrt_myName.m`) called `sqrt_myName(x)` that computes the square root of `x`.
+
+- Copy the `test.m` file to `test_myName.m` and change the names of the functions accordingly.
+
+
+- Before submitting the merge request, verify locally that your code is running properly.
+  Simply execute it
+   ```sh
+   $ matlab -nodesktop -nosplash < test_myName.m
+   ```
+   and verify that no error is reported.
+
+- Create a merge-request.
+
+- Assign either Laurent (@laurent.heirendt) or Sylvain (@sylvain.arreckx) depending on your group and your merge-request will be reviewed by one of us.
+
+<br>
+That's it!